org.apache.hadoop.mapred.MapOutputFile Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.mapred;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.conf.Configurable;
import org.apache.hadoop.fs.Path;
/**
* Manipulate the working area for the transient store for maps and reduces.
*
* This class is used by map and reduce tasks to identify the directories that
* they need to write to/read from for intermediate files. The callers of
* these methods are from child space and see mapreduce.cluster.local.dir as
* taskTracker/jobCache/jobId/attemptId
* This class should not be used from TaskTracker space.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
public abstract class MapOutputFile implements Configurable {
private Configuration conf;
static final String MAP_OUTPUT_FILENAME_STRING = "file.out";
static final String MAP_OUTPUT_INDEX_SUFFIX_STRING = ".index";
static final String REDUCE_INPUT_FILE_FORMAT_STRING = "%s/map_%d.out";
public MapOutputFile() {
}
/**
* Return the path to local map output file created earlier
*
* @return path
* @throws IOException
*/
public abstract Path getOutputFile() throws IOException;
/**
* Create a local map output file name.
*
* @param size the size of the file
* @return path
* @throws IOException
*/
public abstract Path getOutputFileForWrite(long size) throws IOException;
/**
* Create a local map output file name on the same volume.
*/
public abstract Path getOutputFileForWriteInVolume(Path existing);
/**
* Return the path to a local map output index file created earlier
*
* @return path
* @throws IOException
*/
public abstract Path getOutputIndexFile() throws IOException;
/**
* Create a local map output index file name.
*
* @param size the size of the file
* @return path
* @throws IOException
*/
public abstract Path getOutputIndexFileForWrite(long size) throws IOException;
/**
* Create a local map output index file name on the same volume.
*/
public abstract Path getOutputIndexFileForWriteInVolume(Path existing);
/**
* Return a local map spill file created earlier.
*
* @param spillNumber the number
* @return path
* @throws IOException
*/
public abstract Path getSpillFile(int spillNumber) throws IOException;
/**
* Create a local map spill file name.
*
* @param spillNumber the number
* @param size the size of the file
* @return path
* @throws IOException
*/
public abstract Path getSpillFileForWrite(int spillNumber, long size)
throws IOException;
/**
* Return a local map spill index file created earlier
*
* @param spillNumber the number
* @return path
* @throws IOException
*/
public abstract Path getSpillIndexFile(int spillNumber) throws IOException;
/**
* Create a local map spill index file name.
*
* @param spillNumber the number
* @param size the size of the file
* @return path
* @throws IOException
*/
public abstract Path getSpillIndexFileForWrite(int spillNumber, long size)
throws IOException;
/**
* Return a local reduce input file created earlier
*
* @param mapId a map task id
* @return path
* @throws IOException
*/
public abstract Path getInputFile(int mapId) throws IOException;
/**
* Create a local reduce input file name.
*
* @param mapId a map task id
* @param size the size of the file
* @return path
* @throws IOException
*/
public abstract Path getInputFileForWrite(
org.apache.hadoop.mapreduce.TaskID mapId, long size) throws IOException;
/** Removes all of the files related to a task. */
public abstract void removeAll() throws IOException;
@Override
public void setConf(Configuration conf) {
this.conf = conf;
}
@Override
public Configuration getConf() {
return conf;
}
}